Methods for detecting a target microorganism in a sample frequently include the use of an indicator reagent that is acted upon by the target microorganism to form a detectable product. For example, the biological activity may be detected by a catalytic activity associated with a cell, such as a pathogenic microorganism, a biological indicator organism, or a cancer cell.
The detection of a particular biological activity in a sample can be indicative of particular microorganisms in the sample. Bacterial spores, for example, include biological activities (e.g., enzyme activities such as α-glucopyranosidase or β-glucopyranosidase) that may be used in methods (e.g., including rapid methods) detect the presence of viable spores in a sample. Destruction of one of these or other biological activities can be used to verify and/or validate the efficacy of a sterilization process.